Apparatus and method for thawing frozen food

ABSTRACT

Apparatus and method for thawing frozen food for use in a refrigerator appliance with a storage compartment maintained at a temperature between 33°-55° F. There is provided a container for receiving a frozen food load to be thawed within the compartment. An electric fan is in air flow communication with the interior of the container and timer means are provided for energizing and then deenergizing the fan after a predetermined period of operating time whereby the frozen food load may be thawed and allowed to remain in the container subsequent to thawing, the temperature within said container being substantially at the temperature of the storage compartment thus preventing spoilage of the thawed food.

BACKGROUND OF THE INVENTION

This invention relates to food thawing apparatus and method and, moreparticularly, to apparatus and method adapted for incorporation in ahousehold refrigerator which operates to thaw frozen food and maintainthe thawed food at refrigerated temperatures.

The advantages of freezing food for preservation purposes are offset tosome extent by the need to thaw the frozen food before it can be madeready for food preparation. In general, the need to thaw certain foodsbefore cooking or making use of it in food preparation procedures iswell known. Typically, thawing of frozen food can be accomplished byallowing the food to stand at room temperature until it is fully thawed.Such thawing, however, results in a substantial amount of liquid beingdrained from the food. In addition, when the food is allowed to stand atroom temperature, the timing must be such that the food is used promptlyupon thawing or else placed back into the refrigerator to avoid thepossibility of food spoilage. In some cases, it is recommended that thefrozen food be placed in the fresh food compartment of a refrigeratoruntil thawed. This procedure, however, takes a very long time to achievethawing.

Microwave ovens are currently available that have provision for alow-power setting intended to permit thawing of frozen food by means ofelectromagnetic radiation of energy into the food load. Althoughsomewhat beneficial for this purpose, the microwave oven has certaindrawbacks when used for defrosting frozen food. One of the drawbacks isthat the frozen food is heated initially near the surface of the foodload with internal heating (thawing) being a function of the degree ofheat conduction through the food from the surface. Moreover, energyload-in at localized portions of the food, e.g., in the vicinity of abone, can actually cause the food to become fully cooked at theselocations while other portions of the food load are still frozen. Inaddition, once the food load is thawed, it either must be usedimmediately or placed back in the refrigerator to again avoid thepossibility of food spoilage.

In the past, refrigerators have been provided with a frozen food thawingcompartment that is located adjacent to the machine compartment so thatair heated by the machine compartment, such as the condensing unit,flows into the receptacle to warm the frozen food articles and thawthem. See, for example, U.S. Pat. Nos. 2,465,107; 2,467,464; and2,758,452. This type of refrigerator thawing does not avoid thepossibility of food spoilage once the food is thawed and, in fact, maypromote spoilage because of the elevated temperature unless it is usedimmediately or placed in the refrigerator compartment for preservation.

Refrigerators have also been provided with compartments for thawingfrozen food which compartments are insulated and heated by a hot gascircuit in the refrigerating system. See, for example U.S. Pat. No.3,134,242. This type of food thawing system in refrigerators requiresthat a substantial amount of heat be applied in one form or another tothe food items being thawed. In a refrigerating atmosphere, this is notdesirable from an energy saving standpoint as the refrigerator must workharder in order to maintain the proper refrigerated temperature withinthe refrigerator and the thawing chamber must be heavily insulated.Moreover, when the food is thawed, it is maintained at an elevatedtemperature that again could cause spoilage unless removed from thethawing chamber and placed in the refrigerated compartment.

There is, therefore, a need for a reliable, low cost, food thawingapparatus and method suitable for household use. There is a need forsuch an apparatus and method that does not require constant attendanceto avoid food spoilage and for an apparatus and method that uniformlythaws the food load without heating of the food load before completethawing is achieved. By my invention, there is provided an apparatus andmethod for thawing frozen food which will accomplish the above-desiredresults and which is easy to utilize for its intended purpose.

SUMMARY OF THE INVENTION

According to one aspect of my invention, there is provided apparatus andmethod for thawing frozen food for use in a refrigerator appliance witha storage compartment maintained at a temperature of between 33° and 55°F. There is a container for receiving a frozen food load to be thawedwithin the compartment. An electric fan produces a flow of air incommunication with the interior of the container and timer means areused for initially energizing and then deenergizing the fan after apredetermined period of operating time. By this arrangement and method,the frozen food load may be allowed to remain in the containersubsequent to thawing, the temperature within the container beingsubstantially at the temperature of the storage compartment, thuspreventing spoilage of the thawed food.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a refrigerator partially brokenaway to show an exemplary embodiment of the present invention.

FIG. 2 is a fragmentary cross-sectional view of the refrigerator of FIG.1 showing an embodiment of the present invention.

FIG. 3 is a view taken along lines 3--3 of FIG. 2.

FIG. 4 is an alternate embodiment of the present invention shown in FIG.2.

FIG. 5 is a fragmentary cross-sectional view of a portion of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIG. 1 of the drawings, there is illustrated arefrigerator cabinet, including an outer case 1, an upper inner liner 2defining a freezer storage compartment 3 and a lower inner liner 4defining a fresh food storage compartment 5. The compartments areseparated by a partition 6 and the spaces between the liners and theoutside case 1 are filled with suitable insulating material 7. Theaccess opening to the freezer and fresh food compartments arerespectively closed by doors 8 and 9.

Refrigeration for the two compartments is provided by an evaporator 10positioned behind a wall 11 to separate it from food items stored in thefreezer compartment. A fan 14 provides means for circulating air fromthe two compartments over the evaporator 10 and back into thecompartments. It will be understood that the refrigeration system wouldalso include a compressor, a condenser and controls (not shown) tomaintain the fresh food storage compartment 5 at a temperature between33°-55° F., as is well known in the refrigeration trade. Below 33° F.,items in the food storage compartment could freeze and thawing of thefrozen food load would be detrimentally affected. When the frozen foodload is thawed, it is desirable to retain it at 55° F. and below toprevent spoilage.

Typically, the fresh food compartment 5 contains shelves and vegetableand meat pans for storing food items. One such storage pan 16 is shownat the bottom of the fresh food compartment 5. In many refrigerators,including the preferred embodiment shown in the drawings, the shelvesare vertically movable on tracks 18 which are secured to the rear wall20 of the lower inner liner 4. The shelves are movable vertically sothat the user of the refrigerator may arrange them according to thespecific needs of the items to be stored in the fresh food compartment.

Located within the fresh food compartment 5 is a container assembly 24which is used for thawing frozen food items, and particularly, frozenmeat, fowl or fish. The container assembly 24 includes a planar shelf 26which is supported at each side thereof by brackets 28 and 29. Thebrackets 28 and 29 are cantilevered and include a shelf supportinghook-shaped end 22 which is removably inserted into slots 23 of each ofthe tracks 18 such that the brackets are movable vertically along thetracks 18.

The brackets 28 and 29 are attached to both sides of the shelf 26 whichhas a horizontal panel 30 and downwardly depending side walls 32 and 34to which the brackets 28 and 29 are attached. The shelf 26 has aninwardly open channel on both side walls 32 and 34 dimensioned toslidably receive a container 36. Both channels are of the sameconfiguration. For instance as shown in FIG. 5, the channel on side wall32 uses the inner surface 38 of the side wall as the bottom wall 38 andtwo legs 40 and 42 are formed on the inner surface of side wall 32 whichare parallel to and spaced from each other to receive an outwardlyturned lip 44 on each side of the container 36. With this arrangementthen, the container 36 may be gripped, as by handle 48 at the frontthereof, and moved along the channels so that the container 36 may bepartially or completely removed from beneath the shelf 26.

The rear wall 50 of the container 36 has spaced openings in areas 71 and73. Behind the rear wall 50 of the container 36 is a housing 52 havingside walls 54 and 56, a bottom wall 57, a rear wall 58, a top wall 59and a front wall 60. Front wall 60 has spaced openings in areas 62 and64, which areas are surrounded by gaskets 66 and 68, respectively. Areas71 and 73 with their spaced openings in rear wall 50 of the container 35and areas 62 and 64 and their spaced openings in front wall 60 of thehousing 52 are in communicating alignment, respectively, to allow airflow therethrough. Gaskets 66 and 68 form a seal between the front wall60 of housing 52 and the rear wall 50 of container 36. On one sidewithin the housing 52, there is located an electric timer 70 and on theother side within the housing 52 is a small electric fan 72. Withreference to FIG. 3, the housing 52 is secured to the shelf 26 with abracket 74 by any suitable fastening means, such as screws 76. The fan72 is mounted to bottom wall 57 of housing 52 by a U-shaped supportmember 78. It will be noted that the fan 72 is mounted or located withrespect to area 62 in the front wall 60 so that air being moved by thefan blade 75 during operation of the fan will flow through the openingsin area 62 and the aligned openings in area 71 of the rear wall 50 ofthe container 36. With reference to FIG. 2, there is an electricalconduit 77 with a terminal plug 79 that may be connected anddisconnected with a receptacle 81 that supplies electrical power to thetimer 70 and fan 72. With this arrangement, if the user wishes to removethe entire container assembly 24 from the compartment 5, the plug 79 isdisconnected from receptacle 81 and the brackets 28 released from theslots 23 in tracks 18 by raising the shelf 26 and the container assembly24 lifted out of the compartment 5.

Timer 70 may be controlled by the user of the refrigerator by a controlassembly 80 which includes at the front of the shelf 26 a manuallyrotatable knob 82. Secured to the knob 82 is a rod member 84 whichextends from the front of the shelf 26 through guide member 86 to therear of shelf 26 and is rotatably secured to an upstanding support 90secured to top wall 59 of housing 52. Located forward of upstandingsupport 90 is a bevel gear 92 which is secured to rod member 84 androtatable therewith in response to rotation of knob 82. Bevel gear 92meshes with a bevel gear 94 at a right angle thereto which rotates withshaft 96 of the timer 70. With this arrangement then, by rotating knob82, bevel gear 92 rotates through rod member 84 and causes bevel gear 94to also rotate which will operate to set the timer to run for someamount of time. Contrawise, when the timer 70 is running, bevel gear 94through timer shaft 96 rotates and that rotational movement istransmitted to bevel gear 92 through rod member 84 to knob 82. Timer 70is utilized for initially energizing and then deenergizing the fan 72after a predetermined period of operating time set by the user.

The operation of the frozen food thawing apparatus is as follows: Thecontainer 36 is moved along the channels of the downwardly dependingside walls 32 and 34 as previously explained to remove it fromunderneath the shelf 26. The preferred embodiment has a container cover46 that is removed and the frozen food load to be thawed is placedinside. The cover 46 is replaced and the entire container 36 is movedrearwardly along the channels until the rear wall 50 abuts in sealingengagement with the gaskets 66 and 68. The user then rotates knob 82 toset the timer for a desired length of thawing time. Rotational movementof the knob 82 is transmitted through rod member 84 to bevel gear 92, tobevel gear 94 and through timer shaft 96 to the timer 70. When the timershaft 96 is rotated, electrical connections are made so that fan 72 isenergized. Air is caused to flow by fan blade 75 through area 62 in thefront wall 60 of housing 52 and area 71 in the rear wall 50 of container36 into the interior of container 36 and around the frozen food load tobe thawed. The air will be returned to the housing 52 through area 73 ofrear wall 50 and area 64 in the front wall 60 and recirculated by thefan 72 as previously described. The bottom wall 98 of the container 36has corrugations or ribs 37 to enhance air flow around the frozen foodload. As the timer 70 is running, the rotational movement of the timermechanism through shaft 96 and bevel gear 94 causes bevel gear 92 torotate which rotational movement is transmitted through rod member 84 toknob 82. As a result, the knob 82 will rotate back to a zero settingwhen the timer run time has expired. When the time has expired, the fan72 is deenergized by the timer and the frozen food load which has nowbeen thawed will be retained at nearly the same temperature as theinterior of the fresh food compartment thus preventing spoilage of thethawed food.

FIG. 4 shows an alternate embodiment to the frozen food thawingapparatus shown in the other figures, particularly FIG. 2, however, theonly difference in the apparatus is that the container 36 has aplurality of openings 100 that allows ambient air from the compartment 5into the interior of the container 36. In this manner, venting of thecontainer takes place during delivery of the forced air flow to theinterior of the container resulting in the temperature of the air in thecontainer 36 and the air in the compartment 5 being more readilyequalized.

By this food thawing apparatus and method, most frozen foods,particularly meat, fowl and fish, may be thawed much faster than simplyplacing the frozen food in the refrigerator and allow it to thaw. Thefrozen food is thawed with less liquid drainage than if the frozen foodis allowed to thaw at room temperature and the user may thaw the frozenfood and have it retained at proper storage temperatures to avoidspoilage.

The foregoing is a description of the preferred embodiment of theinvention and it should be understood that variations may be madethereto without departing from the true spirit of the invention, asdefined in the appended claims.

What is claimed is:
 1. For use in a refrigerator appliance having astorage compartment maintained at a temperature between 33°-55° F.,apparatus for thawing a frozen food load comprising:a separate containerlocated within the storage compartment for receiving a frozen food loadto be thawed, said container and storage compartment having cooperatingmeans to removably secure the container within the storage compartment;an electric fan in air flow communication with the interior of thecontainer; and manually settable timer means for initially energizingand then deenergizing the fan after a predetermined period of operatingtime; whereby the frozen food load may be thawed and allowed to remainin said container subsequent to thawing, the temperature within saidcontainer being substantially at the temperature of the storagecompartment thus preventing spoilage of the thawed food.
 2. The frozenfood thawing apparatus of claim 1 wherein the interior bottom of thecontainer is corrugated.
 3. The frozen food thawing apparatus of claim 1wherein the container is vented to permit compartment ambient air toflow through the container when the fan is operating.
 4. The frozen foodthawing apparatus of claim 1 wherein electric fan and timer means are ina housing attached to a vertically movable shelf.
 5. The frozen foodthawing apparatus of claim 4 wherein the shelf may be removed from thecompartment.
 6. The frozen food thawing apparatus of claim 4 wherein thecontainer is removable, supported on the vertically movable shelf. 7.The frozen food thawing apparatus of claim 4 wherein the housing and thecontainer have communicating openings for air flow therethrough.
 8. Thefrozen food thawing apparatus of claim 7 wherein a sealing gasketsurrounds the communicating openings.